Since 1889, appendectomy — the surgical removal of the appendix — has been the go-to treatment for acute appendicitis. But a new study finds that going under the knife may not be necessary. For two-thirds of patients, antibiotics may work just as well, or better, than surgery.

Researchers from the Nottingham Digestive Diseaeses Centre NIHR Biomedical Research Unit report that patients with uncomplicated appendicitis may be safely and effectively treated initially with standard antibiotics. Using antibiotics also significantly reduces the risk of complications and death, compared with surgery, the researchers found. For complicated cases, however — those involving perforated appendixes, for example — still need surgical removal.

To compare outcomes, the researchers performed a meta-analysis of four randomized controlled trials involving a total of 900 adult patients with uncomplicated acute appendicitis. Of the 900 participants, 470 received antibiotics and 430 had surgery.

The researchers found that 63% patients who received initial antibiotic treatment were symptom-free after a year and avoided appendectomy. They also had a 31% lower risk of complications compared with the appendectomy group.

However, about 20% of patients who were treated with antibiotics were eventually readmitted to the hospital with recurring symptoms: 13 ended up with complicated appendicitis and needed surgery. Three of the patients were successfully treated with another round of antibiotics, and four had a normal appendix.

In a corresponding editorial, Dr. Olaf Bakker from the Department of Surgery at the University Medical Center Utrecht in the Netherlands, said: “It is questionable whether a failure rate of 20 percent within one year is acceptable.” One major problem is that if antibiotics are used in patients who later require surgery, the delay can increase the risk of complications.

Bakker argues that further research is still needed and until then, “appendectomy for uncomplicated appendicitis will probably continue.”

Indeed, the results are not going to change the standard of care for appendicitis in the U.S., but the authors suggest that an “early trial of antibiotics merits consideration as the initial treatment option for uncomplicated appendicitis.”

The study was published in the April 5 online edition of British Medical Journal.